Chromatin loops are responsible for higher counts of small DNA fragments induced by high-LET radiation, while chromosomal domains do not affect the fragment sizes

2006 ◽  
Vol 82 (4) ◽  
pp. 293-305 ◽  
Author(s):  
Artem L. Ponomarev ◽  
Francis A. Cucinotta
2014 ◽  
Vol 289 (44) ◽  
pp. 30635-30644 ◽  
Author(s):  
Hongyan Wang ◽  
Xiang Wang ◽  
Guangnan Chen ◽  
Xiangming Zhang ◽  
Xiaobing Tang ◽  
...  

High linear energy transfer (LET) radiation from space heavy charged particles or a heavier ion radiotherapy machine kills more cells than low LET radiation, mainly because high LET radiation-induced DNA damage is more difficult to repair. Relative biological effectiveness (RBE) is the ratio of the effects generated by high LET radiation to low LET radiation. Previously, our group and others demonstrated that the cell-killing RBE is involved in the interference of high LET radiation with non-homologous end joining but not homologous recombination repair. This effect is attributable, in part, to the small DNA fragments (≤40 bp) directly produced by high LET radiation, the size of which prevents Ku protein from efficiently binding to the two ends of one fragment at the same time, thereby reducing non-homologous end joining efficiency. Here we demonstrate that Ape1, an enzyme required for processing apurinic/apyrimidinic (known as abasic) sites, is also involved in the generation of small DNA fragments during the repair of high LET radiation-induced base damage, which contributes to the higher RBE of high LET radiation-induced cell killing. This discovery opens a new direction to develop approaches for either protecting astronauts from exposure to space radiation or benefiting cancer patients by sensitizing tumor cells to high LET radiotherapy.


2020 ◽  
Vol 21 (21) ◽  
pp. 8151
Author(s):  
Sharda Kumari ◽  
Shibani Mukherjee ◽  
Debapriya Sinha ◽  
Salim Abdisalaam ◽  
Sunil Krishnan ◽  
...  

Radiation therapy (RT), an integral component of curative treatment for many malignancies, can be administered via an increasing array of techniques. In this review, we summarize the properties and application of different types of RT, specifically, conventional therapy with x-rays, stereotactic body RT, and proton and carbon particle therapies. We highlight how low-linear energy transfer (LET) radiation induces simple DNA lesions that are efficiently repaired by cells, whereas high-LET radiation causes complex DNA lesions that are difficult to repair and that ultimately enhance cancer cell killing. Additionally, we discuss the immunogenicity of radiation-induced tumor death, elucidate the molecular mechanisms by which radiation mounts innate and adaptive immune responses and explore strategies by which we can increase the efficacy of these mechanisms. Understanding the mechanisms by which RT modulates immune signaling and the key players involved in modulating the RT-mediated immune response will help to improve therapeutic efficacy and to identify novel immunomodulatory drugs that will benefit cancer patients undergoing targeted RT.


1989 ◽  
Vol 117 (2) ◽  
pp. 351 ◽  
Author(s):  
Robert W. Atcher ◽  
Angelo Russo ◽  
William G. DeGraff ◽  
Mark Moore ◽  
David J. Grdina ◽  
...  
Keyword(s):  

2008 ◽  
Vol 170 (6) ◽  
pp. 794-802 ◽  
Author(s):  
Torsten Groesser ◽  
Brian Cooper ◽  
Bjorn Rydberg

1992 ◽  
Vol 12 (2-3) ◽  
pp. 33-43 ◽  
Author(s):  
Aloke Chatterjee ◽  
William R. Holley

2021 ◽  
Author(s):  
C. Hartel ◽  
E. Nasonova ◽  
S. Ritter ◽  
T. Friedrich

The mechanism underlying the carcinogenic potential of α radiation is not fully understood, considering that cell inactivation (e.g., mitotic cell death) as a main consequence of exposure efficiently counteracts the spreading of heritable DNA damage. The aim of this study is to improve our understanding of the effectiveness of α particles in inducing different types of chromosomal aberrations, to determine the respective values of the relative biological effectiveness (RBE) and to interpret the results with respect to exposure risk. Human peripheral blood lymphocytes (PBLs) from a single donor were exposed ex vivo to doses of 0–6 Gy X rays or 0–2 Gy α particles. Cells were harvested at two different times after irradiation to account for the mitotic delay of heavily damaged cells, which is known to occur after exposure to high-LET radiation (including α particles). Analysis of the kinetics of cells reaching first or second (and higher) mitosis after irradiation and aberration data obtained by the multiplex fluorescence in situ hybridization (mFISH) technique are used to determine of the cytogenetic risk, i.e., the probability for transmissible aberrations in surviving lymphocytes. The analysis shows that the cytogenetic risk after α exposure is lower than after X rays. This indicates that the actually observed higher carcinogenic effect of α radiation is likely to stem from small scale mutations that are induced effectively by high-LET radiation but cannot be resolved by mFISH analysis.


1971 ◽  
Vol 111 (1) ◽  
pp. 7-8
Author(s):  
MICHEL TER-POGOSSIAN
Keyword(s):  

2018 ◽  
Vol 183 (1-2) ◽  
pp. 60-68 ◽  
Author(s):  
George Iliakis ◽  
Veronika Mladenova ◽  
Mortoga Sharif ◽  
Shipra Chaudhary ◽  
Ifigeneia V Mavragani ◽  
...  

2021 ◽  
Author(s):  
Daria D. Shamina ◽  
Alla V. Boreyko ◽  
Mariia G. Zadneprianetc ◽  
Tatiana S. Hramco ◽  
Marina E. Krupnova ◽  
...  

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